In order to measure electrical characteristics of an inspection object such as an integrated circuit in a state where the inspection object is not separated from a wafer, an electrical connection device including probes to be brought into contact with the inspection object is used. The probes are held, for example, in a state of penetrating guide holes formed in a probe head (for example, refer to PTL 1).
For the probes, those in each of which a shape of a cross section perpendicular to an axial direction is polygonal are also used. For example, probes in each of which a shape of a cross section perpendicular to an axial direction is quadrangular are used for measuring micro electro mechanical systems (MEMS). In this case, a shape of guide holes of a probe head is also formed into a quadrangular shape in response to the shape of each cross section of the probes.